Game suddenly low res and running slow

Randomly last night, my game stopped working properly. All of the meshes became jagged, interacting with objects is now ridiculously delayed to the point where they seemingly no longer work, and the whole thing is just slower. I don’t understand what happened. I added a small shack into a level and some objects in that and then it all went to hell. Deleting all of this does not fix the problem.

Any errors in the output log?

It’s a bit hard to know what you mean from your description. Meshes have become jagged? Stick a screenshot up if possible.

For low res issue, check your Quality settings in Engine Scalability Settings